Fibroids associated with lower chance of unsuspected malignancy

NATIONAL HARBOR, MD. – Women undergoing hysterectomy or myomectomy for benign indications, who also had fibroids, were less likely to have a malignant diagnosis, according to a study presented at the AAGL Global Congress.

These findings could change the conversation when it comes to counseling patients about the risks associated with morcellation, a procedure that was strongly discouraged by the FDA in 2014 due to the concern that it might have the potential to spread malignancy.

“There’s a lot of things going on in the media about morcellation and risk of malignancy at the time of benign fibroid surgery, but this research actually makes apparent the higher risk of malignancy when fibroids are not present,” Farah Alvi, MD, a second-year fellow at Northwestern University, Chicago, said in an interview. Despite the concerns regarding morcellation and malignancy, this research suggests that patients who have fibroids at time of surgery may have a lower chance of malignancy, compared with patients who have other indications for surgery, she explained.

Dr. Alvi and her colleagues studied 2,987 hysterectomy or myomectomy patients with benign indications between January 2005 and December 2014.

Among patients studied, researchers found 33 confirmed malignant or borderline tumors, 16 of 1,790 (0.89%) in the leiomyoma group and 17 of 1,197 (1.42%) in the group with other indications (P = 0.04). The malignancies/borderline tumors included three leiomyosarcomas, two endometrial sarcomas, two endometrioid adenocarcinomas, one granulose cell tumor, three smooth muscle tumors of uncertain malignant potential, three atypical leiomyoma, and one serous papillary borderline ovarian tumor.

Of those with leiomyomata, 1 in 600 patients were diagnosed with leiomyosarcoma, compared with a risk of 1 in 350 for unanticipated malignancy in general.

Patients with surgical indications of symptomatic leiomyoma had an odds ratio of 0.63 (P = .18) for diagnosis of an unanticipated malignancy, compared with those without leiomyoma, according to Dr. Alvi. The odds of malignancy were also reduced in patients with uterine sizes of 15-20 weeks (OR, 0.65; P = .43) and those with specimen sizes of 250-500 grams (OR, 0.68; P = .64).

These findings will have implications for how physicians counsel women undergoing minimally invasive hysterectomy or myomectomy, Dr. Alvi said.

“In counseling patients about morcellation, we often have quoted them an estimated risk of 1 in 458 for leiomyosarcoma, based on the FDA morcellation warnings, and one thing we can learn is that risk is actually much lower than we think it is,” Dr. Alvi said.

The findings also suggest a shift in focus toward identifying the factors that put women at higher risk for malignancy. For example, older age is one of the most significant risk factors identified in the study, she added.